Question

Why do we use standard time ? explain with an example from india?

Answer 1

Using solar time or other means could not be used to tell the exact time. Standard time is the synchronization of clocks inside a region or geographical area to a single time standard. In the 19th century, to help weather forecasting and train travel, Standard time was established. In the 20th century,  Standard time was applied globally. 

Indian Standard Time (IST) is the time used throughout India and Sri Lanka
 
The time offset is UTC+05:30.

In military and aviation,  IST time is designated E* ("Echo-Star").